Police are expanding their investigation into the smuggling and use of drugs involving movie stars and models.

In the latest drug bust of entertainers, police booked popular film star Ju Ji-hun, 27, on suspicion of drug use and arrest warrants were sought for actress Yun Seol-hee, 28, and model Ye Hak-young, 26, for alleged smuggling ecstasy tablets and ketamine into the country from Japan. Two other residents were booked on similar suspicions.

"Besides the suspects on the list we have secured, there are likely more, given the amount of drugs smuggled. Further investigations are unavoidable,'' an officer of the Seoul Metropolitan Policy Agency said.

Police officiers said the entertainers appear to have been tempted to use drugs on assumption that that ecstasy and other drugs kill the appetite, helping them reduce their weight. Ecstasy is a mildly hallucinogenic amphetamine and the most popular illegal drug in Korea, while ketamine, also illegal here, is a veterinary medicine that has a strong hallucinatory effect on humans in dilute doses.

Experts said that more popular stars are blacklisted as suspects who used the drugs smuggled in by Yun.

The latest scandal is jolting the entertainment industry, already reeling following the suicide of actress Jang Ja-yeon, who left a note accusing media and entertainment firms' presidents of forcing her to have sex with them.

Ju is a hallyu (Korean wave) star in Japan and is now expected to lose opportunities to appear in Japanese media, let alone appearances on domestic TV programs or movies. He was scheduled to have a fan meeting in Tokyo next month.

Ju is a model-turned-actor who debuted in the 2006 drama "Princess Hours,'' with the role of a crown prince of Korea. He recently starred in the movies "Antique'' and "The Naked Kitchen'' and the musical "Don Juan.'' He was going to shoot the drama "Tokyo Tower'' next month, but the role is going to be given to another actor.

Ju admitted to using drugs, saying he took them when he was drunk at a party at Ye's house, according to police. Since both Ju and Ye are models-turned-actors, the entertainment industry expects other colleagues to be implicated in the scandal.

Many fans are disappointed. "I was surprised at the news of Ju's drug use. Drug scandals involving entertainers seem to never end,'' said Kim Dong-hyun, 28, a graduate student.

Many other entertainers have also been caught for drug use. Actress Hwang Su-jung was caught using philopon ― an amphetamine ― in November 2001. She was known for her elegant image, but an attempted comeback was unsuccessful even years after the scandal. Singer Psy, or Park Jae-sang, was caught in the same month for smoking marijuana. Actresses Sung Hyun-ah was caught for taking ecstasy in 2002; Kim Boo-seon for marijuana in 2004; and Ko Ho-kyeong for marijuana in 2006.

The drug busts of entertainers continued last year as well, including jazz vocalist Pak Sun-zoo and Steve Kim of hip hop group Uptown.

Some entertainers have campaigned for legalizing the use of drugs such as marijuana. Kim Boo-seon and singer Shin Hae-chul, both caught for drug use, have insisted that marijuana should be legalized in Korea.

However, the difference this time is that Yun and Ye smuggled the narcotics themselves ― police believe they did this to limit the possibility of exposure.

Some experts cited relatively light punishment on drug users as one of the key reasons behind the scandals. Some have successfully returned to the business years afterward.

Bae Kuk-nam, a culture critic, said, "They can make a return after drug scandals but their wrongdoing is engraved in people's memories.''